Mesh Compositions and Methods of Production

ABSTRACT

Methods of forming a composition for treatment, compositions for treatment, and methods of treatment with the compositions are provided. The methods can include coating a synthetic material substrate with a biologic material. A portion of the biologic material can be acid-swelled.

This application is a continuation of U.S. Non-Provisional patentapplication Ser. No. 16/845,155, filed on Apr. 10, 2020, which is acontinuation of U.S. Non-Provisional patent application Ser. No.15/618,341, filed on Jun. 9, 2017 (issued as U.S. Pat. No. 10,653,815 onMay 19, 2020), which claims the benefit of U.S. Provisional PatentApplication No. 62/347,686, filed on Jun. 9, 2016, each of which isincorporated herein by reference in its entirety.

The present disclosure relates to compositions and methods of treatment,and more particularly, to coated mesh compositions and methods ofproduction of compositions for treatment in accordance with the methods.

Biologic materials have been used for regeneration, reinforcement, orrepair of defective or damaged tissues (e.g., hernia repair, abdominalwall repair, breast reconstruction, connective tissue regeneration,tendon or ligament treatment, or combinations thereof). Compared withsynthetics, biologic materials can provide lower risks of rejection,complications, and infections, while allowing regeneration of normaltissue architecture and function. The expense associated with biologicmaterials, however, can increases the overall cost of surgicalprocedures. And although certain biologic materials are incrediblystrong and effective, there remains a need for materials having evengreater strength and long-term structural support.

Synthetic materials are also effective for some applications. Syntheticmaterials can provide strength, lower cost, ready availability,uniformity, biocompatibility, flexibility, and resistance to acids,stress, and cracking. Synthetic materials, however, can trigger aninflammatory response that can lead to a larger degree of scar tissueformation or other complications. In addition, synthetics may notsupport tissue regeneration.

Devices that incorporate the advantages of both synthetic and biologicmaterials are desirable for some applications. To ensure a strong andeffective treatment, however, it may be desirable to use a compositionthat provides a stronger attachment or engagement between thebiocompatible and synthetic materials, resulting in a composition thatreduces or prevents separation between the biologic and syntheticmaterials. Accordingly, methods of treatment including compositions, aswell as compositions used in the methods, are provided.

According to certain embodiments, a method of producing a surgicalmaterial (e.g., a composition) for treatment is provided. The method caninclude providing a synthetic material substrate and providing acollagen-containing tissue matrix (e.g., a biologic material). Themethod can include creating a slurry with the collagen-containing tissuematrix. Creating the slurry can include subjecting a portion of thecollagen-containing tissue matrix to an acid-swelling process to producean acid-swelled tissue matrix. Creating the slurry can include mixingthe acid-swelled tissue matrix with the collagen-containing tissuematrix to produce a slurry having between approximately 5% andapproximately 35% by volume of the collagen-containing tissue matrix inthe slurry as the acid-swelled tissue matrix. The method can includeembedding the synthetic material substrate in the slurry. In certainembodiments, the slurry can have between, e.g., approximately 5% andapproximately 25%, approximately 5% and approximately 15%, orapproximately 5% and approximately 10%, by volume of thecollagen-containing tissue matrix in the slurry as the acid-swelledtissue matrix.

In certain embodiments, the method can include processing thecollagen-containing tissue matrix to reduce a particle size to produce agroup of collagen-containing tissue matrix fragments. At least a portionof the group of collagen-containing tissue matrix fragments can includefrayed ends. In certain embodiments, the acid swelling process caninclude suspending the collagen-containing tissue matrix in acid andincubating the collagen-containing tissue matrix in the acid untilswelling occurs. The acid can be at least one of acetic acid, ascorbicacid, boric acid, carbonic acid, citric acid, hydrochloric acid, lacticacid, tannic acid, phosphoric acid, and sulfuric acid. In certainembodiments, the method can include rubbing or mechanically moving thecollagen-containing tissue matrix slurry into the synthetic materialsubstrate. In certain embodiments, the method can include freeze dryingthe synthetic material substrate and at least a portion of the slurry toform the surgical material. Freeze drying the synthetic materialsubstrate and at least the portion of the slurry can produce a smoothlayer or skin on an outer surface of the surgical material.

Increasing a percentage by volume of the acid-swelledcollagen-containing tissue matrix in the slurry can increase thestiffness of the surgical material. The method can include performing adecellularization process for the collagen-containing tissue matrix. Themethod can include resuspending the slurry in a buffer. The method caninclude incorporating an antimicrobial compound (e.g., chlorehexidine,silver, citric acid, triple antibiotic, or tetracycline) into thesurgical material. The method can include incorporating ananti-inflammatory compound into the surgical material.

The synthetic material substrate can have a variety of different shapesor configurations. In certain embodiments, the synthetic materialsubstrate can include at least one of a porous foam, a planar mesh, amultifilament woven material, a monofilament woven material,multi-leveled layers, or multi-directional layers. A tensile strength ofthe synthetic material substrate can be greater than a tensile strengthof the collagen-containing tissue matrix. The synthetic materialsubstrate can be biocompatible. The synthetic material substrate caninclude at least one of polypropylene, polytetrafluoroethylene,polyester, terephthalate, polyglycolide, or poly-4-hydroxybutyrate. Thesynthetic material substrate can include one or more textured surfaces.

In certain embodiments, the collagen-containing tissue matrix caninclude an acellular tissue matrix. In certain embodiments, thecollagen-containing tissue matrix can include an acellular dermalmatrix. In certain embodiments, the collagen-containing tissue matrixcan include a porcine tissue matrix.

In certain embodiments, the method can include pouring a portion of theslurry into a mold to cover a bottom of the mold with the slurry. Asused herein, the term “mold” will be understood to refer to anycontainer or housing into which the biologic and synthetic materials arepositioned for forming the exemplary compositions or surgical materials.The method can include positioning the synthetic material substratecoated with the slurry into the mold on top of the slurry. The methodcan include pouring the slurry over the synthetic material substratepositioned in the mold to cover the synthetic material substrate. Incertain embodiments, the method can include freeze drying the surgicalmaterial to combine the collagen-containing tissue matrix and thesynthetic material substrate. In certain embodiments, the method caninclude freeze drying the synthetic material substrate and at least aportion of the slurry to form the surgical material. Freeze drying thesynthetic material substrate and at least a portion of the slurryproduces a smooth layer or skin on an outer surface of the surgicalmaterial.

According to certain embodiments, a composition for treatment isprovided. The composition can include a synthetic material substrate anda collagen-containing tissue matrix (e.g., a biologic material) embeddedto, attached to, coating, encapsulating, encasing or covering thesynthetic material substrate. The collagen-containing tissue matrix canbe in the form of a dried sponge that prior to drying included between,e.g., approximately 5% and approximately 35%, approximately 5% andapproximately 25%, approximately 5% and approximately 15%, orapproximately 5% and approximately 10%, by volume of thecollagen-containing tissue matrix slurry subjected to an acid-swellingprocess.

In certain embodiments, the collagen-containing tissue matrix caninclude a group of collagen-containing tissue matrix fragments (e.g., areduced particle size as compared to the collagen-containing tissuematrix). At least a portion of the group of collagen-containing tissuematrix fragments can include frayed ends. In certain embodiments, theslurry can be rubbed or mechanically moved into the synthetic materialsubstrate. In certain embodiments, the synthetic material substrate andat least a portion of the slurry can be freeze dried to form a surgicalmaterial or composition. Freeze drying the synthetic material substrateand at least the portion of the slurry can produce a smooth layer orskin on an outer surface of the composition. In certain embodiments, thecomposition can be compressed after freeze drying.

In certain embodiments, the composition can include an antimicrobialcompound. In certain embodiments, the composition can include ananti-inflammatory compound. The synthetic material substrate can definea three-dimensional form. In certain embodiments, the synthetic materialsubstrate can include at least one of a porous foam, a planar mesh, amonofilament woven material, a multifilament woven material,multi-leveled layers, or multi-directional layers. A biomechanicalstrength of the synthetic material substrate can be greater than abiomechanical strength of the collagen-containing tissue matrix. Thesynthetic material substrate can be biocompatible. The syntheticmaterial substrate can include at least one of polypropylene,polytetrafluoroethylene, polyester, terephthalate, polyglycolide,poly-4-hydroxybutyrate, or combinations thereof.

In certain embodiments, the synthetic material substrate can include oneor more textured surfaces. The collagen-containing tissue matrix caninclude an acellular tissue matrix. The collagen-containing tissuematrix can include an acellular dermal matrix. The collagen-containingtissue matrix can include a porcine tissue matrix. The syntheticmaterial substrate and the dried slurry can form a combined structure.In certain embodiments, at least a portion of the dried slurry caninclude a smooth layer or skin on an outer surface of the composition.In certain embodiments, the composition can be compressed to reduce theoverall thickness of the composition.

According to certain embodiments, a method of treatment is provided. Themethod can include selecting an anatomic site and implanting in or onthe anatomic site a composition as described above. The composition canpromote tissue ingrowth with tissue surrounding the anatomic site. Thecomposition can reduce inflammation at the anatomic site as compared toa synthetic material substrate without the tissue matrix.

According to certain embodiments, a method of forming a composition fortreatment is provided. The method can include providing a syntheticmaterial substrate and a biologic material. The method can includeprocessing the biologic material to reduce a particle size of thebiologic material to form a group of biologic material fragments. Atleast a portion of the group of biologic material fragments can includefrayed ends. In certain embodiments, the method can include coating ormixing the fragments with an anti-inflammatory agent. The method caninclude creating a biologic material slurry with the group of biologicmaterial fragments. The method can include encasing, covering, orcoating at least a portion of the synthetic material substrate with thebiologic material slurry. In certain embodiments, the method can includecausing interlocking of the frayed ends of the biologic materialfragments to strengthen the attachment of the biologic material to thesynthetic material substrate. Interlocking the frayed ends of thebiologic material fragments can also strengthen the attachment of thebiologic material to each other to increase the integrity of theresulting hybrid composition.

According to certain embodiments, a composition for treatment isprovided. The composition can include a synthetic material substrate anda biologic material encasing, attached, or embedded to the syntheticmaterial substrate. The biologic material can be in the form of a driedsponge including a group of biologic material fragments, at least aportion of the group of biologic material fragments including frayedends. Prior to drying, the slurry can be coated over at least a portionof the synthetic material substrate to encase the synthetic materialsubstrate.

According to certain embodiments, a method of treatment is provided. Themethod can include selecting an anatomic site and implanting in or onthe anatomic site a composition described herein.

According to certain embodiments, a method of forming a composition fortreatment is provided. The method can include providing a syntheticmaterial substrate and a biologic material. The method can includecreating a biologic material slurry with the biologic material. Themethod can include covering or coating at least a portion of thesynthetic material substrate with the biologic material slurry. Themethod can include rubbing or mechanically moving the biologic materialslurry into the synthetic material substrate. In certain embodiments,the method can include freeze drying and compressing the composition.Compressing the composition can, e.g., reduce a thickness of thebiologic material layer covering or coating the synthetic materialsubstrate, increase a density of the biologic material layer covering orcoating the synthetic material substrate, and strengthen a structuralstability of the biologic material.

According to certain embodiments, a composition for treatment isprovided. The composition can include a synthetic material substrate anda biologic material attached to the synthetic material substrate. Thebiologic material can be in the form of a dried slurry (or sponge)covering and compressed against the synthetic material substrate.Compression of the slurry after drying (e.g., freeze drying or airdrying) can assist in attaching the biologic material to the syntheticmaterial substrate.

According to certain embodiments, a method of treatment is provided. Themethod can include selecting an anatomic site and implanting in or onthe anatomic site a composition.

According to certain embodiments, a method of forming a composition fortreatment is provided. The method can include providing a syntheticmaterial substrate and a biologic material. The method can includecreating a biologic material slurry with the biologic material. Themethod can include covering or coating at least a portion of thesynthetic material substrate with the biologic material slurry. Themethod can include freeze drying the synthetic material substrate and atleast a portion of the biologic material slurry to form a composition.Freeze drying the synthetic material substrate and at least the portionof the biologic material slurry produces a smooth layer or skin on anouter surface of the composition.

In certain embodiments, the method can include supporting the syntheticmaterial substrate and at least the portion of the biologic materialslurry during freeze drying such that the smooth layer or skin forms onan upper surface and an opposing lower surface of the composition. Incertain embodiments, the method can include reorienting the syntheticmaterial substrate and at least the portion of the biologic materialslurry during freeze drying or between freeze drying processes such thatthe smooth layer or skin forms on an upper surface and an opposing lowersurface of the composition.

In certain embodiments, the method can include freeze drying a firstcomposition in a mold to form a first smooth layer or skin, removing thefirst composition from the mold and removing the first smooth layer orskin (e.g., in the form of a sheet or thin layer) from the firstcomposition, flipping the first smooth layer or skin upside down andplacing the first smooth layer or skin into a mold with the first smoothlayer or skin facing a bottom, inner surface of the mold, pouring thebiologic material slurry onto the first smooth layer or skin to coverthe first smooth layer or skin with the biologic material slurry,positioning a second synthetic material substrate on the biologicmaterial slurry, placing a second biologic material slurry to cover orcoat at least a portion of a second synthetic material substrate suchthat the second biologic material slurry faces an open end of the mold,and freeze drying the second synthetic material substrate, the firstsmooth layer or skin, and the second biologic material slurry to form asecond composition with a second smooth layer or skin on an outersurface of the second composition, the first smooth layer or skinattaching to the second composition during freeze drying resulting inthe second composition including a first surface with the first smoothlayer or skin and a second surface with the second smooth layer or skin.In certain embodiments, the first composition can include only thebiologic material (i.e., not a combination of a biologic material with asynthetic material) to form the first smooth layer or skin to be usedwith the second composition. Thus, one synthetic material substrate canbe used in forming the composition with the first and second smoothlayers or skins. It should be understood that the first smooth layer orskin removed from the first composition includes an outer surface withthe smooth layer or skin and an inner surface on an opposite side of thefirst smooth layer or skin. The second biologic material slurry betweenthe second synthetic material substrate and the inner surface of thesheet of first smooth layer or skin promotes attachment of the innersurface of the sheet of first smooth layer or skin to the secondsynthetic material substrate. In addition, the second biologic materialslurry increases the thickness of the second composition (both beforeand after compression). The resulting composition includes two surfaces(e.g., opposing surfaces), each with a smooth outer layer or skin.

According to certain embodiments, a composition for treatment isprovided. The composition can include a synthetic material substrate anda biologic material attached to the synthetic material substrate. Thebiologic material can be in the form of a slurry freeze dried into asponge and covering the synthetic material substrate. At least a portionof the biologic material can include a smooth layer or skin on an outersurface produced during freeze drying of the slurry.

According to certain embodiments, a method of treatment is provided. Themethod can include selecting an anatomic site and implanting in or onthe anatomic site a composition as described above.

According to certain embodiments, a method of forming a composition fortreatment is provided. The method can include providing a syntheticmaterial substrate. The method can further include creating a biologicmaterial slurry with the biologic material. The method can includeincorporating at least a portion of the biologic material slurry intothe synthetic material substrate to form a composition. Incorporatingthe biologic material slurry into the synthetic material substrate caninclude physically rubbing or otherwise mechanically moving the biologicmaterial slurry into the synthetic material substrate. In certainembodiments, the method can include reducing a particle size of thebiologic material to form a group of biologic material fragments.

Creating the biologic material slurry can include creating acid-swelledbiologic material with at least a portion of the biologic material. Themethod can include contacting the biologic material with an acid andincubating the biologic material until swelling occurs. The acid can beat least one of acetic acid, ascorbic acid, boric acid, carbonic acid,citric acid, hydrochloric acid, lactic acid, tannic acid, phosphoricacid, and sulfuric acid. The method can include mixing the acid-swelledbiologic material with non-swelled biologic material to form a biologicmaterial slurry. Increasing a percentage by volume of the acid-swelledbiologic material in the biologic material slurry can increase astiffness of the resulting composition.

In certain embodiments, an antimicrobial compound can be incorporatedinto the composition. The antimicrobial compound can be at least one ofchlorhexidine, silver (ionic, elemental, or salts), citric acid, tripleantibiotic, tetracycline, other antibiotics, or combinations thereof. Incertain embodiments, an anti-inflammatory compound can be incorporatedinto the composition.

In certain embodiments, the synthetic material substrate can be in theform of a three-dimensional form or construct. The synthetic materialsubstrate can include at least one of a porous foam, a planar mesh, amonofilament woven material, a multifilament woven material,multi-leveled layers, multi-directional layers, or combinations thereof.A mechanical strength (tensile strength, burst strength, or sutureretention strength) of the synthetic material substrate can be greaterthan a biomechanical strength of the biologic material. The syntheticmaterial substrate can be biocompatible. In certain embodiments, thesynthetic material substrate can be at least one of polypropylene,polytetrafluoroethylene, polyester, terephthalate, polyglycolide,poly-4-hydroxybutyrate, or combinations thereof. In certain embodiments,the synthetic material substrate can include one or more texturedsurfaces.

The biologic material can include a tissue matrix. In certainembodiments, the biologic material can include a collagen containingtissue matrix. In certain embodiments, the tissue matrix can include anacellular tissue matrix. In certain embodiments, the tissue matrix caninclude an acellular dermal matrix. In certain embodiments, the tissuematrix can include a porcine tissue matrix or a human tissue matrix.

In some cases, the biologic material slurry can be mechanically forcedor processed (e.g., physically rubbed, mechanically moved, or otherwisemechanically processed) into the synthetic material substrate. Incertain embodiments, physically rubbing or mechanically moving andcompressing the biologic material slurry into the synthetic materialsubstrate creates a coating of the biologic material slurry on an outersurface of the synthetic material substrate, thereby encasing at least aportion of the synthetic material substrate in the biologic materialslurry.

The method can include pouring a portion of the biologic material slurryinto a mold to cover a bottom of the mold with the biologic materialslurry. The method can include positioning the synthetic material coatedwith, encased within, or embedded within the biologic material slurryinto the mold on the biologic material slurry. The method can includepouring additional biologic material slurry over the synthetic materialpositioned in the mold to cover the synthetic material. The method caninclude drying, e.g., freeze drying, the composition to attach or embedthe biologic material to the synthetic material (and/or cover, encaseand/or coat the synthetic material with the biologic material).

According to certain embodiments, a composition for treatment isprovided. The composition can include a synthetic material and abiologic material embedded to, attached to, coating, or covering thesynthetic material. The biologic material can be in the form of abiologic material slurry. The biologic material slurry can beincorporated into the synthetic material by physically rubbing,mechanically moving, or otherwise mechanically processing the biologicmaterial slurry into the synthetic material.

In certain embodiments, a particle size of the biologic material can bereduced to form a biologic material fragment for forming the biologicmaterial slurry. In certain embodiments, processing of the biologicmaterial can include cell removal and processing to remove antigeniccomponents. In certain embodiments, the processing can be performedprior to mechanical processing of the biologic material to reduce theparticle size of the biologic material. In certain embodiments, theprocessing can be performed after mechanical processing of the biologicmaterial to reduce the particle size of the biologic material. Incertain embodiments, the biologic material can be processed by adecellularization process.

In certain embodiments, at least a portion of the biologic materialslurry can include acid-swelled biologic material. In certainembodiments, the composition can include an antimicrobial compound. Incertain embodiments, the composition can include an anti-inflammatorycompound.

In certain embodiments, the synthetic material can define athree-dimensional form or construct. In certain embodiments, thesynthetic material can include at least one of a porous foam, a planarmesh, a multifilament woven material, multi-leveled layers,multi-directional layers, or combinations thereof. The biomechanicalstrength of the synthetic material can be greater than the biomechanicalstrength of the biologic material. The synthetic material can bebiocompatible. In certain embodiments, the synthetic material caninclude at least one of polypropylene, polytetrafluoroethylene,polyester, terephthalate, or combinations thereof. In certainembodiments, the synthetic material can include one or more texturedsurfaces.

The biologic material can include a tissue matrix. In certainembodiments, the tissue matrix can include an acellular tissue matrix.In certain embodiments, the tissue matrix can include an acellulardermal matrix. In certain embodiments, the tissue matrix can include aporcine tissue matrix.

Physically rubbing, mechanically moving or otherwise mechanicallyprocessing the biologic material slurry into the synthetic material canforce at least a portion of the biologic material slurry into thesynthetic material. In certain embodiments, physically rubbing,massaging, mechanically moving, or otherwise mechanically processing thebiologic material slurry into the synthetic material can create acoating of the biologic material slurry on an outer surface of thesynthetic material, wherein the coating may be embedded within openingor porous portions in the synthetic material. The synthetic material andthe biologic material slurry can be freeze dried and/or air dried toembed or attach the biologic material to the synthetic material (and/orcover or coat the synthetic material with the biologic material).

According to certain embodiments, a method of producing a composition orsurgical material is provided. The method can include providing asynthetic material and providing a biologic material. The method caninclude creating a biologic material slurry with the biologic material.The method can include incorporating the biologic material slurry intoand covering the surface of the synthetic material to form thecomposition. In particular, incorporating the biologic material slurryinto and covering the surface of the synthetic material can includemechanically processing or forcing (e.g., physically rubbing,mechanically moving, or the like) the biologic material slurry into thesynthetic material. Thus, the biologic material slurry can bemechanically forced into openings in the surface(s) of the syntheticmaterial to substantially cover the outer surfaces of the syntheticmaterial. The method can include at least partially covering a defect orimplant site with the composition.

The composition can promote tissue ingrowth and regeneration of tissuesurrounding the composition after implantation. Including betweenapproximately 5% and approximately 35% by volume of acid-swelledbiologic material slurry to form the composition can stabilize thecomposition. Physically rubbing, compressing, otherwise mechanicallymoving the biologic material slurry into the synthetic material canproduce a strong attachment between the synthetic and biologic material.Suspending or reorienting the composition during freeze drying resultsin smooth layers or skin formed on one or more surfaces of thecomposition, providing a greater structural integrity to thecomposition.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a flow chart of an exemplary process of preparing acomposition, according to certain embodiments;

FIG. 2 is a front view of an exemplary composition including 0% byvolume of acid-swelled biologic material as a percentage of the biologicmaterial component, according to certain embodiments;

FIG. 3 is a front view of an exemplary composition including 5% byvolume of acid-swelled biologic material as a percentage of the biologicmaterial component, according to certain embodiments;

FIG. 4 is a front view of an exemplary composition including 10% byvolume of acid-swelled biologic material as a percentage of the biologicmaterial component, according to certain embodiments;

FIG. 5 is a front view of an exemplary composition including 25% byvolume of acid-swelled biologic material as a percentage of the biologicmaterial component, according to certain embodiments;

FIG. 6 is a front view of an exemplary composition including 50% byvolume of acid-swelled biologic material as a percentage of the biologicmaterial component, according to certain embodiments;

FIG. 7 is a front view of an exemplary composition including 100% byvolume of acid-swelled biologic material as a percentage of the biologicmaterial component, according to certain embodiments;

FIG. 8 is a magnified view of an exemplary composition including 0% byvolume of acid-swelled biologic material as a percentage of the biologicmaterial component with trichrome staining, according to certainembodiments;

FIG. 9 is a magnified view of an exemplary composition including 5% byvolume of acid-swelled biologic material as a percentage of the biologicmaterial component with trichrome staining, according to certainembodiments;

FIG. 10 is a magnified view of an exemplary composition including 10% byvolume of acid-swelled biologic material as a percentage of the biologicmaterial component with trichrome staining, according to certainembodiments;

FIG. 11 is a magnified view of an exemplary composition including 25% byvolume of acid-swelled biologic material as a percentage of the biologicmaterial component with trichrome staining, according to certainembodiments;

FIG. 12 is a magnified view of an exemplary composition including 50% byvolume of acid-swelled biologic material as a percentage of the biologicmaterial component with trichrome staining, according to certainembodiments;

FIG. 13 is a magnified view of an exemplary composition including 100%by volume of acid-swelled biologic material as a percentage of thebiologic material component with trichrome staining, according tocertain embodiments;

FIG. 14 is a cross-sectional view of an exemplary uncompressedcomposition, according to certain embodiments;

FIG. 15 is a top view of the exemplary uncompressed composition of FIG.14, according to certain embodiments;

FIG. 16 is a scanning electron microscope (SEM) image of an exemplarynon-compressed composition showing a synthetic material encased by abiologic material, according to certain embodiments;

FIG. 17 is a chart of average stress at 50% strain of non-compressedexemplary compositions including 3% and 7% by volume of solid biologicmaterial and 5% by volume of acid-swelled biologic material as apercentage of the biologic material component, according to certainembodiments;

FIG. 18 is a cross-sectional view of an exemplary compressed compositionincluding a synthetic material encased by a biologic material, accordingto certain embodiments;

FIG. 19 is a scanning electron microscope (SEM) image of an exemplarycompressed composition showing a synthetic material encased by abiologic material, according to certain embodiments;

FIG. 20 is a gross image of an explant of a composition including asynthetic mesh, showing a rat abdominal wall defect treated with thecomposition, with an arrow showing tissue adhesion to the syntheticmesh, according to certain embodiments;

FIG. 21 is a gross image of a cross-section of an explant of acomposition including a synthetic mesh used to treat a defect in a ratabdominal wall, according to certain embodiments;

FIG. 22 is a gross image of a non-compressed composition explantincluding a synthetic material coated with a biologic material, showinga rat abdominal wall defect treated with the non-compressed composition,according to certain embodiments;

FIG. 23 is a gross image of a cross-section of a non-compressedcomposition explant including a synthetic material coated with abiologic material, used to treat a defect in a rat abdominal wall,according to certain embodiments;

FIG. 24 is a hematoxylin and eosin (H&E) stained image of an explant ofa rat abdominal wall defect treated with a polypropylene mesh without abiologic material coating, according to certain embodiments;

FIG. 25 is a hematoxylin and eosin (H&E) stained image of an explantfrom a rat abdominal wall defect treated with a non-compressedcomposition including a synthetic material coated with a biologicmaterial, according to certain embodiments;

FIG. 26 is a hematoxylin and eosin (H&E) stained section showing bloodvessels visible in a non-compressed composition explant including asynthetic material coated with a biologic material, according to certainembodiments;

FIG. 27 is a smooth muscle actin (SMA) stained section of an explantfrom a rat abdominal wall defect treated with a polypropylene meshwithout a biologic material coating, according to certain embodiments;

FIG. 28 is a smooth muscle actin (SMA) stained image of an explant fromrat abdominal wall defect treated with a non-compressed compositionincluding a synthetic material coated with a biologic material,according to certain embodiments;

FIG. 29 is a chart of a size of an original rat abdominal wall defectand a rat abdominal wall defect treated with a polypropylene meshwithout a biologic material coating and a non-compressed compositionincluding a synthetic material coated with a biologic material,according to certain embodiments;

FIG. 30 is a hematoxylin and eosin (H&E) stained image showingcompressed compositions including a synthetic material coated with abiologic material implanted in a rat subcutaneous space for four weeks,according to certain embodiments;

FIG. 31 is a microscopy image of reduced size biologic materialincluding tendrils or frayed ends, and interlocking of the tendrils orfrayed ends, according to certain embodiments;

FIG. 32 is a side view of an uncompressed composition including asynthetic material coated with a biologic material, according to certainembodiments;

FIG. 33 is a side view of a compressed composition including a syntheticmaterial coated with a biologic material, according to certainembodiments;

FIG. 34 is a microscopy image of a composition including a syntheticmaterial coated with a biologic material without a skin layer, accordingto certain embodiments;

FIG. 35 is a microscopy image of a composition including a syntheticmaterial coated with a biologic material with a skin layer, according tocertain embodiments; and

FIG. 36 is a diagrammatic view of a process for forming a skin layer onboth sides of a composition including a synthetic material coated with abiologic material, according to certain embodiments.

DESCRIPTION OF CERTAIN EXEMPLARY EMBODIMENTS

Reference will now be made in detail to certain exemplary embodimentsaccording to the present disclosure, certain examples of which areillustrated in the accompanying drawings. Wherever possible, the samereference numbers will be used throughout the drawings to refer to thesame or like parts.

In this application, the use of the singular includes the plural unlessspecifically stated otherwise. In this application, the use of “or”means “and/or” unless stated otherwise. Furthermore, the use of the term“including”, as well as other forms, such as “includes” and “included”,is not limiting. Any range described herein will be understood toinclude the endpoints and all values between the endpoints.

The section headings used herein are for organizational purposes onlyand are not to be construed as limiting the subject matter described.All documents, or portions of documents, cited in this application,including but not limited to patents, patent applications, articles,books, and treatises, are hereby expressly incorporated by reference intheir entirety for any purpose.

The present disclosure is directed to exemplary compositions fortreatment of structural defects, such as abdominal defects. Thecompositions include a combination of biologic and synthetic materials.In particular, the exemplary compositions include biologic materialsattached to or embedding the synthetic material such that thecomposition can be manipulated during surgery without separation of thebiologic and synthetic materials. The compositions can be folded orrolled to pass through a trocar or other opening for laparoscopic orother minimally invasive surgery. The attachment between the biologicand synthetic materials provides strength to the composition whileallowing the composition to be flexed or otherwise manipulated duringimplantation. Furthermore, the synthetic material can provide a highlevel of tensile strength, burst strength, and/or suture retentionstrength, while the biologic material provides improved biologicresponses, including a reduction in inflammation, a reduction in orprevention of scar or fibrotic tissue formation around the implant, anda reduction in or prevention of adhesion with surrounding viscera.

The hybrid composition allows the biologic material to function as abarrier to block the recognition by the host defense system, therebyreducing the foreign body response to the synthetic material. Thebiologic material can integrate with the host tissue and allows forvascularization, thereby reducing the possibility of infection. Further,the durability of the synthetic material provides mechanical advantages(e.g., strength and limited stretchability) for a treatment site,resulting in a durable repair of the host tissue.

Biologic Materials

Various human and animal tissues (e.g., biologic materials) can be usedto produce products or compositions for treating patients. For example,various tissue products for regeneration, repair, augmentation,reinforcement, and/or treatment of human tissues that have been damagedor lost due to various diseases and/or structural damage (e.g., fromtrauma, surgery, atrophy, and/or long-term wear and degeneration) havebeen produced. Such products can include, for example, acellular tissuematrices, tissue allografts or xenografts, and/or reconstituted tissues(i.e., at least partially decellularized tissues that have been seededwith cells to produce viable materials).

In certain embodiments, these products or compositions can be completelyor partially decellularized to yield acellular tissue matrices orextracellular tissue materials to be used for patients. For example,various tissues, such as skin, intestine, bone, cartilage, muscle(skeletal or otherwise), fascia, dermis nerve tissue (e.g., nerve fibersor dura), tendons, ligaments, or other tissues can be completely orpartially decellularized to produce tissue products useful for patients.In some cases, these decellularized products can be used withoutaddition of exogenous cellular materials (e.g., stem cells). In certaincases, these decellularized products can be seeded with cells fromautologous sources or other sources to facilitate treatment. Suitableprocesses for producing acellular tissue matrices are described below.

Tissue products can be selected to provide a variety of differentbiological and mechanical properties. For example, an acellular tissuematrix or other tissue product can be selected to allow tissue ingrowthand remodeling to assist in regeneration of tissue normally found at thesite where the matrix is implanted. For example, an acellular tissuematrix, when implanted on or into fascia, may be selected to allowregeneration of the fascia without excessive fibrosis or scar formation.In certain embodiments, the tissue product can be formed from ALLODERM®or STRATTICE™, which are human and porcine acellular dermal matrices,respectively. Alternatively, other suitable acellular tissue matricesare available, as described further below. For example, a number ofbiological scaffold materials are described by Badylak et al. Badylak etal., “Extracellular Matrix as a Biological Scaffold Material: Structureand Function,” Acta Biomaterialia (2008),doi:10.1016/j.actbio.2008.09.013. In certain embodiments, thecompositions discussed herein can be formed from or can include a tissueproduct, a synthetic material, or both.

The term “acellular tissue matrix,” (e.g., ATM) as used herein, refersgenerally to any tissue matrix that is substantially free of cellsand/or cellular components. Skin, parts of skin (e.g., dermis), andother tissues such as blood vessels, heart valves, fascia, cartilage,bone, fascia, muscle (skeletal or non-skeletal) and nerve connectivetissue may be used to create acellular matrices within the scope of thepresent disclosure. Acellular tissue matrices can be tested or evaluatedto determine if they are substantially free of cell and/or cellularcomponents in a number of ways. For example, processed tissues can beinspected with light microscopy to determine if cells (live or dead)and/or cellular components remain. In addition, certain assays can beused to identify the presence of cells or cellular components.

In general, the steps involved in the production of an acellular tissuematrix include harvesting the tissue from a donor (e.g., a human cadaveror animal source) and cell removal under conditions that preservebiological and structural function. The ATM can be produced from anycollagen-containing soft tissue and musculo-skeletal tissue (e.g.,dermis, fascia, pericardium, dura, umbilical cords, placentae, cardiacvalves, ligaments, tendons, vascular tissue (arteries and veins such assaphenous veins), neural connective tissue, urinary bladder tissue,ureter tissue, or intestinal tissue), as long as the above-describedproperties are retained by the matrix. Moreover, in certain embodiments,the tissues in which the above ATMs are placed include any tissue thatcan be remodeled by invading or infiltrating cells. Relevant tissuesinclude, without limitation, skeletal tissues such as bone, cartilage,ligaments, fascia, and tendon. Other tissues in which any of the aboveallografts can be placed include, without limitation, skin, gingiva,dura, myocardium, vascular tissue, neural tissue, striated muscle,smooth muscle, bladder wall, ureter tissue, intestine, and urethratissue.

While an acellular tissue matrix may be made from one or moreindividuals of the same species as the recipient of the acellular tissuematrix graft, this is not necessarily the case. Thus, for example, anacellular tissue matrix may be made from porcine tissue and implanted ina human patient. Species that can serve as recipients of acellulartissue matrix and donors of tissues or organs for the production of theacellular tissue matrix include, without limitation, mammals, such ashumans, nonhuman primates (e.g., monkeys, baboons, or chimpanzees),pigs, cows, horses, goats, sheep, dogs, cats, rabbits, guinea pigs,gerbils, hamsters, rats, or mice.

One exemplary method for making (or preparing) an ATM can include thesteps of: optionally providing a tissue sample from a mammal; removingall, or substantially all, of the cells from the tissue sample resultingin a decellularized tissue; and contacting the decellularized tissuewith a DNA nuclease that removes all, or substantially all, of the DNAfrom the decellularized tissue, thereby resulting in an ATM.Decellularization of a tissue can be accomplished using a number ofchemical or enzymatic treatments known in the art and described in,e.g., U.S. Pat. No. 5,336,616 (the disclosure of which is incorporatedby reference in its entirety). For example, cells can be removed from atissue by incubating the tissue in a processing solution containingcertain salts (e.g., high concentrations of salts), detergents (e.g.,mild or strong detergents), enzymes, or combinations of any of theforegoing. Strong detergents include, e.g., ionic detergents such as,but not limited to: sodium dodecyl sulfate, sodium deoxycholate, and3-[(3-chloramidopropyl)-dimethylammino]-1-propane-sulfonate. Milddetergents include, e.g., polyoxyethylene (20) sorbitan mono-oleate andpolyoxyethylene (80) sorbitan mono-oleate (TWEEN 20 and 80), saponin,digitonin, TRITON X-100™, CHAPS, and NONIDET-40 (NP40). The use of thedetergent TRITON X-100™, a trademarked product of Rohm and Haas Companyof Philadelphia, Pa., has been demonstrated to remove cellularmembranes, as detailed in U.S. Pat. No. 4,801,299, the entire contentsof which are incorporated by reference in their entirety. Alternatively,decellularization can be accomplished using a variety of lysogenicenzymes including, but not limited to, dispase II, trypsin, andthermolysin.

A tissue can be treated once or more than once (e.g., two, three, four,five, six, seven, eight, nine, or 10 or more times) with a processingsolution. A tissue can be treated more than one time with the sameprocessing solution or can be treated with several different processingsolutions in series. For example, a tissue can be treated with oneprocessing solution multiple times or the tissue can be treated with afirst processing solution and subsequently with a second processingsolution.

As the processing solution can contain chemicals or agents that would beirritating or inflammatory when administered to a mammalian subject,washing can be performed to substantially remove the processing solutionfrom the tissue. In some embodiments, a tissue can be washed one or more(e.g., two, three, four, five, six, or more than seven) times followingtreatment with a processing solution or the tissue can be washed one ormore times between processing solution treatments. For example, a tissuecan be treated with a first processing solution and then washed threetimes before treatment with a second processing solution. Alternatively,rather than or in addition to, components of the processing solution maybe neutralized by inhibitors, e.g., dispase II byethylenediaminetetraacetic acid (EDTA) or trypsin by serum.

Methods for determining the extent of decellularization are known in theart and include, e.g., cell-counting/trypan blue exclusion assays (onany cells collected from a treated tissue) or various microscopy methodssuch as direct immunostaining of a decellularized tissue section usingantibodies that bind to specific cell markers (e.g., markers of the cellnucleus, mitochondria, or cell cytoplasm). Such methods are describedin, e.g., Ramos-Vara, JA (2005) Vet Pathol 42: 405-426 and Hayat (2002)Microscopy, Immunohistochemistry, and Antigen Retrieval Methods: ForLight and Electron Microscopy, 1^(st) Ed. Springer, the disclosures ofeach of which are incorporated by reference in their entirety.

Synthetic Materials

The synthetic materials discussed herein can be fabricated from avariety of different biocompatible and/or resorbable materials. Forexample, the synthetic materials can include polypropylene (PP),polytetrafluoroethylene (PTFE), polyester (i.e., polyethyleneterephthalate (PET)), polyglycolide (PGA), poly-4-hydroxybutyrate(P4HB), or combinations thereof. In certain embodiments, the syntheticmaterial can be in the form of a mesh substrate, e.g., a multifilamentwoven material, a monofilament woven material, or combinations thereof.In certain embodiments, the synthetic material can be in the form of aporous foam, multi-leveled and/or multi-directional layers, orcombinations thereof. In certain embodiments, the synthetic material canbe printed with a three-dimensional printer to produce athree-dimensional scaffold.

In certain embodiments, the synthetic material can be fabricated from anon-absorbable material, an absorbable material, or a material that is acombination of both non-absorbable and absorbable materials. “Absorbablematerial” can be defined herein as any material that can be degraded inthe body of a mammalian recipient by endogenous enzymatic or cellularprocesses. Depending upon the particular composition of the material,the degradation products can be recycled via normal metabolic pathwaysor excreted through one or more organ systems. A “non-absorbablematerial” can be defined herein as any material that cannot be degradedin the body of a mammalian recipient by endogenous enzymatic or cellularprocesses.

In certain embodiments, the synthetic material can provide the abilityto produce various textures (e.g., loops and hooks, rough textures, orcombinations thereof) to assist in attachment or handling. For example,the textured surface of the synthetic material can assist withattachment of the biologic material to the synthetic material.

The synthetic material can be formed in various colors to act as avisual aid during final implantation or for identification duringsubsequent procedures or if explant is ever desired. For example, thecolor of the synthetic material can differ from the biologic materialand the surrounding tissue to better accommodate the implant site cavityand provide ease of suture location during the surgical procedure.

The synthetic material can be used to provide a controlled reinforcement(e.g., a rebar), strength, thickness, rate of biologic degradation, orcombinations thereof, in varying regions of the composition. Forexample, the synthetic material can be positioned in areas of thecomposition that will require the most strength to provide support tothe defect site.

In certain embodiments, cohesion can be provided during layering of thebiologic and synthetic materials or components. In certain embodiments,different layers of synthetic material can be at periodic anglesrelative to one another (e.g., similar to manufacturing of plywood) toproduce a multidirectional strength within the composition. Inparticular, the synthetic material can extend in different directionsand/or at different angles to provide greater strength and support tothe composition.

In certain embodiments, rather than a synthetic material or substrate, abiologic substrate material (e.g., a biologic mesh) can be used. Forexample, the biologic substrate material can be fabricated from anybiocompatible material (e.g., silk, a cellulose matrix, or combinationsthereof) suitable for coating and/or embedding with biologic material. Ahybrid composition formed from two biologic materials can thereby beformed.

Composition Preparation

The compositions discussed herein include a combination of biologicmaterials and synthetic materials. In particular, the compositionsgenerally include a sheet of synthetic material covered with andattached to or embedded into biologic materials. The compositions can beused to treat defective or damaged tissue, or to reinforce existingtissues. The compositions provide beneficial properties provided of boththe biologic and synthetic materials, and further provide improvementsin ease of suturability, strength of suture points, a wide array ofmanufacturability (e.g., shape, size, or thickness), decrease ininfection due to the biologic material, incorporation of anti-microbialagents, layered technology to control a rate of degradation, elution ofenzymes and anti-microbial agents, and a reduction in inflammation. Thecompositions also provide for a strong attachment between or embeddingof the biologic and synthetic materials. In particular, the compositionscan be flexible while maintaining the attachment between the biologicand synthetic materials, such that the compositions can be manipulatedeasily during surgery without separation of the components. For example,the compositions can be rolled and passed through a trocar into animplantation site without separation of the synthetic material from thebiologic material.

The compositions can be in the form of bio-synthetic hybrid surgicalthree-dimensional scaffolds for tissue treatment, attachment,reinforcement or reconstruction that minimizes complications andpromotes tissue ingrowth, leading to overall improved surgical outcomes.The inherent biomechanical strength of the synthetic material can bemuch higher than that of biologic material alone. The composition can bemanufactured to any shape and/or size, while maintaining the biologicaladvantages typically associated with biologic materials (e.g., rapidrevascularization, cell repopulation, white cell migration, orcombinations thereof). Therefore, the exemplary compositions lendthemselves to a wide array of surgical applications in a variety ofsites including abdominal surgery, urologic applications, thoracicsurgery, orthopedic surgery, breast reconstruction or augmentation, orother surgical applications in which composite materials may be of used.The devices can be used in minimally invasive or open surgeries.

With reference to FIG. 1, one embodiment of a process of preparing acomposition is provided. The processing of the biologic materialdescribed herein can be selected to accomplish desired cell or antigenremoval, while ensuring that the biologic material retains the abilityto support tissue regeneration, rapid revascularization and cellrepopulation, and does not induce a significant inflammatory responsewhen implanted. It should be understood that one or more steps of theexemplary process can be omitted, and the order of some steps may bechanged.

At step 100 of FIG. 1, the harvested biologic material can bepre-processed. For example, the biologic material or component can beharvested from a tissue site such as the dermis, fatty tissue,peritoneum, the intestines, and can be pre-processed in preparation forpreparing the composition. Such preprocessing may include removal ofunwanted tissues or related structures and storage prior to use.

At step 102, the particle size of the biologic material can be reduced.For example, the originally harvested biologic material can be reducedin size to produce a group of biologic material fragments. In certainembodiments, a tissue or meat chopper/grinder can be used to reduce theparticle size of the biologic material. The biologic material can bereduced in particle size such that the group of biologic materialfragments are substantially similar in size and/or configuration orwithin a preselected size range. In certain embodiments, the size and/orconfiguration of the biologic material fragments can be regulated basedon a selection of the grinder, the size of the rotor, or the size of thestator used for grinding; alternatively, the tissue can be filtered orselected to produce desired size distributions. In some embodiments, ameat chopper/grinder, a mill, or other similar mechanical processingdevice can be used to reduce the particle size of the biologic materialin a liquid at room temperature.

In certain embodiments, the biologic material can be reduced in sizesuch that the biologic material fragments or fibers have frayed ends. Incertain embodiments, a predetermined setting of the rotor and stator ofthe grinder can be used to produce the desired tendrils or frayed endsof the biologic material fragments. FIG. 31 is a microscopy image ofreduced size biologic materials at approximate 30× magnification. Thefragments of the biologic material include tendrils or frayed ends 186.FIG. 31 illustrates an example of the tangling or interlocking 187 ofthe tendrils or frayed ends 186 of the fragments. As an example, thefragments with frayed ends 186 can be formed by shear during thechopping and/or grinding process. The frayed ends 186 can promoteinterlocking 187 between the biologic material fragments duringformation of the composition, resulting in a strong overall structure ofthe composition.

At step 104, the biologic material fragments can be further processed.In certain embodiments, the biologic material fragments can be processedto remove cells and/or antigenic materials such as DNA, antigenicepitopes (e.g., alpha-galactose residues). In certain embodiments, theprocessing can be performed prior to reducing the size of the biologicmaterial by mechanical processing. Alternatively, tissue processing(such as cell removal) can be performed before fragment formation orsimultaneously therewith. In certain embodiments, the frayed ends (or aportion of the frayed ends) of the biologic material fragments can becoated with an anti-inflammatory compound or mixed with such compoundsto prevent or reduce inflammation due to implantation or the surgicalprocedure.

The order of the initial processing and size reduction steps may bevaried. In certain embodiments, the biologic material can bepre-processed (e.g., as described in step 100), a size reduction of thebiologic material can be performed after pre-processing (e.g., asdescribed in step 102), and further processing steps can be taken afterthe size reduction of the biologic material (e.g., as described in step104). In certain embodiments, the biologic material can bepre-processed, further processing steps can be taken afterpre-processing, and size reduction of the biologic material can beperformed after both the pre-processing and processing steps. In certainembodiments, size reduction of the biologic material can initially beperformed, pre-processing of the biologic material can be performedafter the size reduction, and further processing can be performed afterthe pre-processing step.

At step 106, a slurry can be prepared with the biologic materialfragments. In certain embodiments, due to the size reduction of thebiologic material, the fragments in a solution can form the disclosedslurry. In certain embodiments, after step 104, the biologic materialfragments can be centrifuged after each step during processing in orderto pellet the tissue and remove the old solution. After the nextsolution is added, the pellet can be resuspended and allowed optionallyallowed to incubate or wash in the new solution. The new solution can beremoved from the slurry by centrifuging. This process can be repeatedduring each processing step. The process of preparing the slurry caninclude an acid-swelling procedure of at least a portion (e.g., fivepercent) of the biologic material fragments. The acid-swelling procedurecan include the steps of selecting a portion (e.g., 5%) of the biologicmaterial slurry (based on a volume of the biologic material slurry),centrifuging the selected slurry to pellet the biologic material,removing the old solution, resuspending the pellet in a volume of acidsolution that is equal to the volume of old solution removed in theprevious step, incubating the slurry (e.g., for 1-8 hours atapproximately 33-40° C.), and combining the acid-swelled biologicmaterial with the rest of the non-acid-swelled biologic material slurry.

In certain embodiments, the concentration of the acid solution used forthe acid-swelling procedure can affect the final characteristics of thecomposition. For example, a certain concentration of the acid solutioncan result in a slurry having multiple visible dermal fibers, while adifferent concentration of the acid solution can result in a slurryhaving a more liquid consistency with fewer visible dermal fibers. Theresulting different concentrations can affect attachment of the biologicmaterial to the synthetic material. In particular, the amount ofacid-swelled biologic tissue by volume and the concentration of the acidsolution can affect the structural stability of the resultingcomposition. In certain embodiments, formation of the biologic materialslurry can include between, e.g., 5-25%, 5-20%, 5-15%, or 5-10%, ofacid-swelled biologic tissue by volume, resulting in strong structuralstability of the composition.

In certain embodiments, the biologic material slurry can include, e.g.,0-100%, 0-95%, 0-90%, 0-85%, 0-80%, 0-75%, 0-70%, 0-65%, 0-60%, 0-55%,0-50%, 0-45%, 0-40%, 0-35%, 0-30%, 0-25%, 0-20%, 0-15%, 0-10%, 0-5%,5-95%, 10-90%, 15-85%, 20-80%, 25-75%, 30-70%, 35-65%, 40-60%, 45-55%,5-35%, 5-30%, 5-25%, 5-20%, 5-15%, 5-10%, 5%, 10%, 25%, 50%, or 100%, ofacid-swelled biologic material by volume, with the remaining slurryincluding non-acid-swelled material. In preferred embodiments, thebiologic material slurry can include, e.g., 5-35%, 5-30%, 5-25%, 5-20%,5-15%, or 5-10%, of acid-swelled biologic material by volume, with theremaining slurry including non-acid-swelled material. Too muchacid-swelled material (e.g., above approximately 35% by volume) canresult in higher levels of inflammation and biologic degradation uponimplantation. Conversely, an insufficient amount of acid-swelledmaterial (e.g., below approximately 5% by volume) can result in a lackof structural stability of the composition. Therefore, the amount ofacid-swelled biologic material can be controlled to reduce inflammationand to provide sufficient structural stability to the composition. Thetolerance for inflammation and need for structural stability may varybased on the intended use.

The biologic material fragments can be washed one or more times andcentrifuged to remove excess water or buffer. The pellet of biologicmaterial can be resuspended in citric acid and incubated atapproximately 37 C for approximately four hours until swelling occurs.In certain embodiments, the pH of the acid in which the biologicmaterial is resuspended can be in the range of approximately 1-6,approximately 1-4, approximately 1.8-2.2, or about 2. The volume of acidused can be substantially equal to the volume of solution removed aftercentrifugation in order to maintain the solid percentage the same in thebiologic material.

After acid swelling, the swelled biologic material can be mixed withnon-swelled biologic material to form a slurry containing a specificpercentage of swelled biologic material. As an example, a slurry caninclude dermal acellular tissue fragments resuspended in a liquid, andvarying the percentage of swelled biologic material in the slurryaffects the properties of the final composition. For example, increasingthe percentage by volume of acid-swelled biologic material in a slurrycan increase the stiffness of the resulting composition. In certainembodiments, a 100 percent acid-swelled slurry can be formed. In suchembodiments, no dilution with non-swelled biologic material is made.

In certain embodiments, the biologic material can undergo an additionalprocessing step(s). The processing of the biologic material can beselected to accomplish desired cell or antigen removal, while ensuringthat the biologic material retains the ability to support tissueregeneration, rapid revascularization, cell repopulation, white cellmigration, or combinations thereof, and does not induce a significantinflammatory response when implanted. The processing of the biologicmaterial can be performed at one or more stages of the process describedherein.

After the slurry of acid-swelled and non-swelled biologic material hasbeen formed, the slurry can be placed in an appropriate buffer. Forexample, a suitable buffer can be sodium citrate buffer, PBS, or otherbuffers. In certain embodiments, the biologic material slurry can be atapproximately three percent or seven percent by volume of solid biologicmaterial. In certain embodiments, resuspending the slurry in the sodiumcitrate buffer can be performed prior to acid swelling.

At step 108, the biologic material slurry can be incorporated into asynthetic material to cover the outer surfaces of the syntheticmaterial. In particular, the biologic material slurry can bemechanically forced, rubbed, or processed such that at least some of thebiologic material is forced into openings in the outer surface of thesynthetic material, thereby forming a film of biologic material on theouter surfaces of the synthetic material.

In certain embodiments, antimicrobial compounds (e.g., chlorhexidine,silver, citric acid, triple antibiotic, tetracycline, or combinationsthereof) and/or anti-inflammatory compounds (e.g., for reduction ofinflammation and/or anti-scarring), fibronectin, or combinationsthereof) can be incorporated into the biologic material slurry and/orthe synthetic material. In certain embodiments, the synthetic materialcan be in the form of a three-dimensional construct (e.g., a porousfoam, a mesh, multi-leveled and/or multi-directional layers, orcombinations thereof) that provides a three-dimensional scaffold for thebiologic material. The synthetic material or component provides strengthand sutureability to the composition, while the biologic material canmask the synthetic material to promote tissue ingrowth, reduceinflammation and/or scar formation, and minimize complications.

In certain embodiments, the biologic material slurry can be incorporatedinto the synthetic material by mechanically forcing or processing (e.g.,physically rubbing, otherwise mechanically moving, or the like) at leasta portion of the biologic material slurry into the synthetic material.Mechanically forcing or processing the biologic material slurry into thesynthetic material can create a stronger attachment or engagementbetween the biologic and synthetic material, thereby preventingseparation between the materials during use. Mechanically forcing orprocessing the biologic material slurry into the synthetic materialforces portions of the biologic material into openings in the outersurface of the synthetic material and creates a thin coating of thebiologic material on the outer surfaces of the synthetic material.

A portion of the biologic material slurry can be poured into a mold suchthat the bottom of the mold is covered by slurry. As discussed herein,the mold can be any structure or container used for shaping theresulting composition after the drying process. In certain embodiments,the mold can define a substantially rectangular, circular, oval, square,polygon, or curvilinear configuration. The coated or embedded syntheticmaterial can be positioned within the mold on top of the slurry, andadditional biologic material slurry can be poured over the syntheticmaterial such that the slurry covers the synthetic material. It shouldbe understood that the amount of slurry poured onto the bottom of themold and over the synthetic material can be selected based on thedesired thickness of the final composition.

At step 110, the coated synthetic material and the biologic materialslurry can be dried, for example, by freeze drying. During the freezedrying process, the biologic material coating covering the outersurfaces of the synthetic material allows for a stronger attachment orengagement between the biologic material slurry surrounding thesynthetic material in the mold and the synthetic material. Inparticular, the biologic material forced or compressed into thesynthetic material and forming the coating provides a surface againstwhich the biologic material slurry can attach. Further, the biologicmaterial forced or compressed into the synthetic material creates astronger attachment or engagement between the biologic material and thesynthetic material during the freeze drying process due to interlockingof the biologic material around the synthetic material. The freezedrying process can be performed under conditions that maintain thedesired biological and structural properties associated with thebiologic and synthetic materials.

In certain embodiments, when the biologic material slurry and thesynthetic material are positioned in the mold for freeze drying, oneside of the composition is positioned against an inner surface of themold, while the opposing side of the composition is exposed to the air(e.g., vacuum air). During the freeze drying process, collagen fibrilsgradually form through each layer of the composition and latch on toadjacent material to create an attachment. When the collagen fibrilsreach the uppermost and exposed layer of the composition, since there isno additional material to attach to, the collagen fibrils form asubstantially smooth and flat layer, surface or skin. In general, thelowermost and side surfaces positioned within the mold form the collagenfibril bonds, but result in a rougher surface than the smooth layerformed on the uppermost and exposed layer. Unlike rough surfaces thatcreate more friction and can flake off during use, the smooth layerreduces or prevents flaking of the composition due to reduced frictionand strong attachment. As an example, FIG. 34 shows a microscopy imageof a hybrid sponge without a smooth surface or skin layer, and FIG. 35shows a microscopy image of a hybrid sponge with a smooth surface orskin layer.

In certain embodiments, a smooth skin layer can be formed on or added tothe composition during the freeze drying process. In certainembodiments, rather than using a mold structure that encloses all of thesurfaces except for the upper surface, the composition can be freezedried in a mold structure that provides space around the sides of thecomposition (e.g., exposes multiple sides of the sponge or composition).Thus, only the bottom surface is positioned against the mold and theremaining surfaces can be exposed to air such that smooth surfaces orskin can form on most of the outer surfaces of the composition. Incertain embodiments, rather than using a mold that encloses all of thesurfaces except for the upper surface, the composition can be freezedried on a substantially planar support structure that allows for thetop and sides of the composition to be exposed to the air. Smoothsurfaces or skin can thereby form on most of the outer surfaces of thecomposition.

In certain embodiments, after the smooth surfaces have formed on the topand sides of the composition, the composition can be suspended orrepositioned to expose the bottom surface to air such that a smoothsurface or skin can form on the bottom surface. Thus, smooth surfaces orskin can form on all of the surfaces of the composition. In certainembodiments, the orientation of the composition can be varied one ormore times during the freeze drying process such that smooth surfaces orskin form on all of the surfaces of the composition. In certainembodiments, only one side of the composition can be coated with thebiologic material slurry for freeze drying and, once the smooth surfaceor layer has formed, the composition can be flipped and the opposingside can be coated with the biologic material slurry for freeze drying,thereby achieving smooth surfaces or skin on both sides of the biologicmaterial. In certain embodiments, the composition can be positioned onone of the side surfaces during the freeze drying process such that thetop and bottom surfaces of the composition form the smooth surfaces orskin. In certain embodiments, a support structure can suspend or holdthe composition during the freeze drying process in a configuration thatexposes all sides (or at least the top and bottom sides) of thecomposition to allow the exposed sides to form the smooth surfaces orskin. The low friction surfaces results in a structurally strongercomposition with reduces or no flaking of the material.

In certain embodiments, rather than or in addition to using a dryingprocess that exposes multiple sides of the composition, a skin layerfrom one uncompressed sponge can be removed and repositioned such thatthe skin side is in contact with the inside bottom surface of the mold(e.g., not exposed to the atmosphere), biologic material slurry ispoured over the first skin within the mold, and a second composition(including a synthetic material coated with the biologic materialslurry) is positioned over the biologic material slurry such that thebiologic material slurry coating the synthetic material is exposed atthe opening of the mold. Freeze drying is performed again. The side ofthe second composition exposed to the atmosphere forms the skin layerwhile the previously placed skin layer maintains its composition andattaches to the second composition via the biologic material slurry,thereby forming a composition with skin layers on opposing sides.

FIG. 36 shows a diagrammatic view of the process for forming the smoothsurface or skin layer on a composition (e.g., a hybrid sponge).Initially, at step A, a first hybrid composition 188 is formed by freezedrying the composition 188 in a mold 190. After freeze drying, the firsthybrid composition 188 includes a first skin layer 192 (e.g., a toplayer of the first hybrid sponge 188) formed on the surface of thecomposition 188 exposed through the top opening of the mold 190. Incertain embodiments, the first hybrid composition 188 can be formed fromboth a biologic material and a synthetic material, and the first skinlayer 192 can be removed while discarding the remaining portions of thecomposition 188. In certain embodiments, the composition 188 can beformed only from the biologic material without the synthetic material.Thus, after removal of the first skin layer 192 from the composition188, only a portion of the biologic material can be discarded withoutnecessitating discarding of the synthetic material, resulting in a morecost-effective process.

At step B, the first hybrid composition 188 can be removed from the mold190 and the first skin layer 192 is removed (e.g., sliced) from thefirst hybrid composition 188 (e.g., in the form of a sheet). Afterremoving the first skin layer 192 from the first hybrid composition 188,the first skin layer 192 includes an outer surface with the smoothsurface and an inner surface that originally faced the inside of thefirst hybrid composition 188. At step C, the first skin layer 192 isflipped upside down and placed within a mold 190 such that the smoothsurface of the first skin layer 192 faces the inside surface of thebottom of the mold 190. Biologic material slurry is poured over theinner surface of the first skin layer 192. A synthetic material 194coated with biologic material is positioned over the biologic materialslurry on the first skin layer 192, and additional biologic materialslurry is poured on top of the synthetic material 194. The syntheticmaterial 194, the biologic material slurry, and the first skin layer 192can be freeze dried to form the final hybrid composition 198. Thebiologic material slurry within the mold 190 promotes attachment of theinner surface of the first skin layer 192 to the synthetic material 194.In addition, the biologic material slurry increases the thickness of thefinal hybrid composition 198 (both before and after compression).

The surface of the final hybrid composition 198 exposed at the openingof the mold 190 forms a second skin layer 196. At step D, the hybridcomposition 198 can be removed from the mold 190. The hybrid composition198 therefore includes one surface with the first skin layer 192 and anopposing surface with the second skin layer 196. It should be understoodthat the skin layers can be formed on different surfaces of the hybridcomposition and do not necessarily need to be disposed on opposingsurfaces of the hybrid composition. In addition, the process can berepeated to produce several skin layers that can be used to line theinside surfaces of the mold, thereby resulting in a hybrid compositionthat includes multiple sides with skin layers.

At step 112, the composition can be stabilized by additional steps toform a stable three-dimensional scaffold matrix. In certain embodiments,additional stabilization can be performed to maintain the structuralintegrity of the composition when exposed to fluids. For example,suitable stabilization processes can include various cross-linking orother processes to produce a 3-D shape. In certain embodiments, duringuse, the composition can be manipulated (e.g., rolled) to introduce thecomposition into an implant location, and the composition can further berehydrated to expand into the original or natural configuration.

In certain embodiments, at step 114, in addition to or alternatively tomechanically forcing or processing the biologic material slurry into thesynthetic material, a compression step can be performed to incorporatethe biologic material slurry with the synthetic material and/or toincrease the density of the biologic material embedding or coating thesynthetic material. Although shown in FIG. 1 as occurring after step112, it should be understood that step 114 can occur at any stage of theprocess. The compression step can generally be performed on a hydratedcomposition or sponge (e.g., the composition can be hydrated after thefreeze drying step, or the composition can be stabilized incarbodiimide). In certain embodiments, the compression step can beperformed on a freeze-dried composition. In particular, a coating of thebiologic material slurry can be placed on one or more sides of thesynthetic material. Next, the composition can be freeze dried. Afterfreeze drying, the composition can be compressed on both sides at apredetermined pressure. In certain embodiments, a non-compressed spongeor composition can be hydrated and a predetermined load can be placed onthe hydrated non-compressed sponge or composition for a specific amountof time (e.g., approximately two minutes). In certain embodiments, thesponge or composition can be placed back into a freeze dryer to dryagain. In certain embodiments, rather than or in addition to freezedrying, the sponge or composition can be air dried. In particular, afterthe initial freeze drying procedure in step 110 that forms thesponge-like or porous structure, drying of the composition can beperformed by either freeze drying, air drying, or both.

The thickness of the sponge or composition can be adjusted by modifyingthe thickness of the non-compressed sponge or composition, the load usedfor compression, the compression time, the amount of biologic materialslurry used before freeze drying, or combinations thereof. As anexample, the initial thickness of the freeze dried biologic materialslurry can be approximately 1 cm prior to compression and can be reducedto approximately 0.25 cm after compression. For example, FIGS. 32 and 33are side views of an uncompressed hybrid sponge and a compressed hybridsponge.

In certain embodiments, biologic material slurry can be rubbed, coatedor embedded over the synthetic material such that essentially all of theouter surfaces of the synthetic material are coated with the biologicmaterial slurry, a predetermined amount of biologic material slurry canbe poured into the bottom of a mold, the coated synthetic material canbe positioned over the biologic material slurry in the mold, and apredetermined amount of biologic material slurry can be poured over thecoated synthetic material. The mold can be freeze dried to form thehybrid composition. After freeze drying, the composition can be removedfrom the mold and a load can be imparted on the composition to compressthe composition. The amount of biologic material slurry placed at thebottom of the mold and over the coated synthetic material can beselected based on the desired final thickness of the composition. Forexample, equal amounts of the biologic material slurry can be placed atthe bottom of the mold and over the coated synthetic material to ensurethat the synthetic material is in the middle of the final composition.However, the amount of biologic material slurry at the bottom of themold can be different from the amount over the coated synthetic materialif it is desired for the synthetic material to be closer to one side ofthe composition. Multiple compression steps can be performed byrepeating the process of adding biologic material slurry to the bottomof the mold, coating the composition, adding biologic material slurryover the composition, and freeze drying the new composition prior tocompression. Adding more biologic material slurry results in a thickerfinal composition. The desired final thickness of the compositiongenerally dictates how much biologic material slurry is added before andafter the first compression (and subsequent compressions).

Compression of the biologic material against the synthetic materialembeds the biologic material into the synthetic material and results ina more dense coating of the biologic material, thereby strengthening theoverall structure of the composition. Compression of the biologicmaterial slurry against the synthetic material also stabilizes theoverall shape of the composition and promotes structural stability afterformation. During the freeze drying step described above, the biologicmaterial embedded into synthetic material and forming a coating improvesattachment of the biologic material slurry to the synthetic material andimproves attachment of the biologic materials to each other.

In certain embodiments, the compression step can be repeated. Forexample, biologic material slurry can be poured to the bottom of a mold,the previously compressed composition can be coated with a subsequentlayer of the biologic material slurry and placed within the mold, andbiologic material slurry can be poured over the previously compressedcomposition. The mold can be freeze dried to form the hybridcomposition. Next, the newly formed composition can be compressedagainst the previously compressed composition, thereby embedding orincorporating the additional biologic material into the compressedbiologic material. In some embodiments, at step 116, after thecompression step, the composition can be stabilized.

A predetermined amount of force can be applied during the compressionstage, and a predetermined period of time of compression can beutilized. In particular, an approximately 1020 gram weight was usedduring an initial compression step for approximately one minute, and ina subsequent compression step an approximately 2040 gram weight wasadded and the composition was compressed for another minute.Approximately 25 mL of biologic material slurry was placed in the moldbelow the bottom of the coated synthetic material, and approximately 25mL of biologic material slurry was placed on top of the coated syntheticmaterial prior to freeze drying. Using such amounts of biologic materialslurry resulted in a hybrid composition approximately 1 cm in height. Itshould be noted that the height of the hybrid composition also dependson the height of the mold. For example, the same volume of biologicmaterial slurry produces a thinner hybrid composition in a larger mold.In certain embodiments, rather than adding additional biologic materialslurry after the first compression, additional weight can be added toincrease the force of compression in the second compression stage. Theforces and amounts are examples only and can be varied based on the sizeof the samples and desired product features.

In certain embodiments, multiple compression steps can be incorporatedinto the process of forming the composition to add alternative materialsor components (e.g., not biologic material slurry) to either side of thehybrid composition. For example, a layer of the alternative material canbe placed at the bottom of a mold, the compressed composition can beplaced in the mold over the alternative material, and another layer ofthe alternative material can be placed over the compressed composition.The mold can be placed in a freeze dryer to form a subsequentcomposition. After freeze drying, the composition can be removed fromthe mold and compressed.

In certain embodiments, at step 118, a surface coating can be added tothe compressed composition. For example, the surface coating can be 100%acid-swelled biologic material slurry, gelatin, or combinations thereof.The surface coating provides for a smoother surface of the composition,resulting in no or less surface flaking of the composition.

EXAMPLES

With reference to FIGS. 2-7, front views of exemplary compositions 150in the form of sponges having differing percentages by volume ofacid-swelled biologic material (e.g., tissue) are provided. The biologicmaterial in these experiments was formed with porcine acellular dermalmatrix. Formation of the biologic material involved the steps 100-106and step 110 as shown in FIG. 1 and as described above. In particular,the process of producing compositions with differing percentages (byvolume) of acid-swelled biologic material involves the steps describedbelow. The particle size of the biologic material was reduced. Thetissue was hand cut into samples of approximately 1 inch×1 inch squaretiles. The samples were fed through a meat grinder. Phosphate bufferedsaline (PBS) was added to the ground tissues, and the samples werefurther fed through a rotary cutting instrument, which was repeated 3-5times to grind the tissues to the desired, uniform size. The groundtissues were frozen.

Next, a biologic material slurry was prepared with the processedbiologic material. The pellet and a buffer were combined in a blender.The blender was pulsed to achieve a homogeneous suspension. The targetsolid percentage (3%) was measured with a CEM® moisture/solid analyzer.Next, the tissue underwent an acid-swell procedure. The desiredpercentage of the slurry to be swelled was removed (5%, 10%, etc.),centrifuged and decanted. The volume of decant supernatant was noted. Avolume of acid d equal to the volume of the decanted supernatant wasadded, and the mixture was mixed well to resuspend the pellet. Thepellet was incubated. The swelled tissue slurry was added back to thenon-swelled tissue slurry, and mixed well. 20-50 mL of the mixed slurrywas poured into stainless steel well molds or trays. The composition wasthen freeze dried. The filled stainless steel well molds were placedonto lyophilization shelves, and the material was lyophilized.

The biologic material slurry was further used in producing thesynthetic-biologic hybrid compositions, as described below. Inparticular, the biologic material pellet was prepared using the processdescribed above, and the biologic material slurry was prepared with thepellet. A pellet with buffer was homogenized mechanically. The targetwas 5% solid percentage for rubbing into the synthetic (polypropylene)mesh. The target was 3% solid percentage for use as a biologic sponge onthe top and bottom of the synthetic (polypropylene) mesh. The acid-swellprocess was performed for both the 3% and 5% (by volume) biologicslurry. The process included removing the desired percentage of theslurry to be swelled (5%-25%), and centrifuging and decanting. Thevolume of decant supernatant was noted. A volume of acid equal to thevolume of the decanted supernatant was added. The mixture was mixed wellto resuspend the pellet and incubated. The swelled tissue slurry wasadded back to the non-swelled tissue slurry and mixed well.

Next, the biologic material slurry was incorporated into the syntheticmaterial. The synthetic polypropylene mesh was cut 5 mm smaller than thestainless steel well molds. 5% solid slurry (with the desired swelledtissue percent) was incorporated into the precut synthetic polypropylenemesh by rubbing the slurry into the mesh by hand. Half of the desiredtotal volume of the 3% slurry (with the desired swelled tissue percent)was poured into the 2 up stainless steel well mold and would become thebottom layer of the biologic sponge. The synthetic mesh containing theincorporated 5% slurry material was placed into the mold over the poured3% slurry. Care was taken to achieve planar placement of the syntheticmaterial over the poured 3% slurry without trapping air pockets. A wavefront placement is recommended. The second half of the total volume ofthe 3% slurry was poured into the stainless steel well molds to createthe top layer of the biologic sponge. Since a total volume of 50 mL wasused, 25 mL of the slurry was poured at this stage. Next, thecomposition was freeze dried.

FIGS. 2-7 show Examples 1-6 of the compositions 150 includingapproximately 0%, 5%, 10%, 25%, 50%, and 100%, respectively, by volumeof acid-swelled biologic material in the slurry used to form thecomposition 150, with the remainder including non-swelled biologicmaterial. As noted above, an increase in the percentage of acid-swelledbiologic material results in an increase in composition 150 stiffness.As such, the composition 150 in FIG. 2 exhibits greater flexibility thanthe composition 150 in FIG. 7. Each composition 150 is dimensioned asapproximately two inches by two inches and has been processed tostabilize the shape. The amount of acid-swelled biologic materialaffects the pliability of the composition or sponge. Sponges containingan increased percentage of acid-swelled biologic material becomeprogressively stiffer and less pliable than compositions or spongescontaining less acid-swelled biologic material.

FIGS. 8-13 show magnified views of exemplary compositions including 0%,5%, 10%, 25%, 50% and 100% acid-swelled biologic material by volume,respectively. In particular, FIGS. 8-13 show sponge collagen degradationas assessed by trichrome staining. Sponges containing up to andincluding 50% acid-swelled tissue by volume demonstrate minimal collagendegradation by trichrome staining. In certain embodiments, trichrome canbe used to pick up degraded or damaged collagen. In contrast, degradedcollagen (indicated by the arrows in FIG. 13) were clearly visible insponges produced with 100% acid-swelled biologic material by volume.

The compositions formed by placing the biologic material slurry aroundthe synthetic material without physically rubbing or otherwisemechanically moving the biologic material into the synthetic material,without compression of the biologic material against the syntheticmaterial, and without formation of the smooth surfaces resulted in aweak attachment between the biologic and synthetic materials, ultimatelyleading to the biologic material separating and peeling away from thesynthetic material. In particular, although the biologic material stayedintact around the synthetic material, the attachment between thebiologic material and the synthetic material failed.

FIGS. 14 and 15 show cross-sectional and top views of an alternativeexemplary composition 170 prototype including a biologic material 172and a synthetic material 174 disposed between the biologic material 172(e.g., a non-compressed hybrid sponge or composition). In certainembodiments, formation of the biologic material 172 b can involve thesteps 100-106 and step 110 as shown in FIG. 1 and as described above. Incertain embodiments, after step 112 of FIG. 1, the hybrid sponge can besliced on both sides up to a desired thickness while maintaining thesynthetic material 174 in the middle of the hybrid sponge. Althoughillustrated as substantially rectangular in form, in certainembodiments, the composition 170 can be formed into a variety ofconfigurations depending on the application of the composition 170. Incertain embodiments, the configuration of the composition 170 can bedetermined by the mold used during formation of the composition 170. Incertain embodiments, the composition 170 can be formed as substantiallyrectangular in configuration and can be manually trimmed or customizedby a user depending on the desired application.

The composition 170 includes approximately seven percent by volume ofsolid content, e.g., the biologic material 172, and approximately fivepercent by volume of acid-swelled biologic material. In certainembodiments, the composition 170 can be formed by the process describedin FIG. 1. In particular, the biologic material 172 slurry wasphysically rubbed or mechanically moved into the synthetic material 174such that the biologic material 172 was forced into portions of thesynthetic material 174 and created a thin coating on the outer surfacesof the synthetic material 174. The biologic material 172 was thereforeincorporated into the mesh of the synthetic material 174 and created astronger attachment between the biologic and synthetic materials 172,174 to prevent subsequent separation of the biologic and syntheticmaterials 172, 174 during use. In compositions including 100% ofacid-swelled biologic material 172 by volume it was found that asignificant amount of force was needed to remove or separate thebiologic material 172 from the synthetic material 174. In certainembodiments, rubbing of the biologic material 172 was used to remove thebiologic material 172 from the synthetic material 174.

During magnified analysis of the formed compositions, interconnectionbetween the biologic and synthetic materials 172, 174 was found to occurduring the physical rubbing and/or compression stage. Suchinterconnection provided for a greater structural integrity of thecomposition by allowing the remaining biologic material 172 to encasethe synthetic material 174 during the freeze drying process. Inparticular, rather than attaching directly to the synthetic material174, the biologic material 172 poured or coated onto the syntheticmaterial 174 was able to encase portions of the synthetic material 174during the rubbing and/or compression stage.

FIG. 16 is a scanning electron microscope (SEM) image of the composition170 of FIGS. 14 and 15 showing a synthetic material 174 encased by abiologic material 172. Experimentation was performed to determine thecompression or stress values for the composition 170 at approximately50% strain. In particular, the average stress at 50% strain ofnon-compressed sponges or compositions containing 3% and 7% by volume ofa solid material and 5% by volume of the biologic material is providedin FIG. 17. The composition including 3% by volume of the solid materialhas an average stress value of approximately 1.27 kPA and thecomposition 170 including 7% by volume of the solid material has anaverage stress value of approximately 3.88 kPa. In addition, based onthe results, it was determined that stress values can be modulated byvarying the percentage of the biologic material in the composition.

In Vivo Rat Studies

Rat models were used for in vivo studies of the exemplary compositionsdiscussed herein. The compositions included approximately seven percentby volume of solid biologic material and approximately five percent byvolume of acid-swelled biologic material. The in vivo testing wasperformed to investigate the biologic response of the rat model to apolypropylene mesh as compared to a hybrid mesh composition (e.g., thebiologic material physically rubbed and/or compressed into the syntheticmaterial, and the biologic and synthetic materials molded together) whenrepairing an abdominal wall defect of the rat model.

Lewis rats were implemented for the experimentation. A longitudinalmid-abdominal incision was made to expose an area of the abdominal wallthat measures approximately 4 cm×3 cm. A bilateral longitudinallyoriented full thickness defect (approximately 4 cm×3 cm) was created inthe abdominal wall by removing all tissues including membranous Scarpa'sfascia, rectus muscle, the transverses fascia and peritoneum. Eachabdominal wall defect was repaired with a polypropylene mesh (e.g., acontrol group) or a hybrid composition (e.g., 7% solid biologic materialby volume, no electron beam processing—a test group) substantially equalto the size of the defect (e.g., approximately 4 cm×3 cm). Inparticular, the polypropylene mesh and the hybrid composition wereinterpositionally implanted to cover the defect in the respective ratmodels. The mesh and composition were implanted dry and rehydrated atthe end of the procedure. Three rats were used for each type of implant.Three and six week time points were studied. Each of the rats survivedfor three or six weeks post implantation. After three or six weeks, therats were euthanized and the implants, with at least 1 cm of surroundingnormal tissue, were removed for gross and histological analysis.

Three Week Study

Adhesion was observed for the polypropylene only mesh (e.g., the arrowin FIG. 20) and no intestinal adhesion was observed for the hybrid meshcomposition. In addition, the biologic material maintained a strongattachment to the synthetic material due to the physical rubbing and/orcompression of the biologic material into the synthetic material duringfabrication. Prior to implanting the polypropylene mesh and thecomposition, the size of the implants was approximately 4 cm in the Ydirection and 3 cm in the X direction. Three weeks after implantation inthe rat model, the hybrid composition contracted to approximately 3.2 cmin the Y direction and approximately 2.8 cm in the X direction. Threeweeks after implantation in the rat model, the polypropylene meshcontracted to approximately 2.5 cm in both the Y and X directions (e.g.,FIG. 29). The hybrid composition therefore contracted less than thepolypropylene mesh alone. Therefore, the hybrid composition can maintainthe overall configuration for longer periods of time to provide therequisite support to defect in the rat model post-implantation.

Gross images and hematoxylin and eosin (H&E) stained images of thepolypropylene mesh and the hybrid composition after implantation in therat model were obtained. The hybrid explant composition thickness wasmeasured to be two or more times greater than the thickness of thepolypropylene mesh explants (e.g., FIGS. 21 and 23). In addition, thepolypropylene mesh showed a greater amount of inflammation than thehybrid composition (e.g., FIGS. 24 and 25). Both the polypropylene meshand the hybrid composition had good integration with the host tissue. Inparticular, the hybrid composition allowed for tissue ingrowth from thehost tissue. However, the implant-host interface of the polypropylenemesh included inflammation around the junction between the polypropylenemesh and the host tissue. Thus, the hybrid composition integrates withthe host tissue while preventing or reducing the amount of inflammation.

The H&E stained views of the polypropylene mesh and hybrid compositionthree weeks after implantation in the rat model also showed that thepolypropylene mesh included a greater amount of inflammation than thehybrid composition. Multiple large blood vessels formed in the hybridcomposition from the tissue ingrowth (e.g., arrows in FIG. 26). Vimentinstained tissue sections of the polypropylene mesh and the hybridcomposition were obtained three weeks after implantation in the ratmodel. Strong staining in both the polypropylene mesh and the hybridcomposition indicated that several types of fibroblasts were present. Itshould be understood that the implants could include fibroblasts and/ormyofibroblasts. The smooth muscle actin stained tissue sections of thethree week polypropylene mesh and the hybrid composition explantsfurther showed stronger staining in the polypropylene mesh, indicatingthat there are more myofibroblasts present in the polypropylene meshthan in the hybrid composition (e.g., FIGS. 27 and 28). The stainingfurther shows blood vessel formation in both the polypropylene mesh andthe hybrid composition.

Three Week Study Results

The three week histology study indicated advantageous properties of thehybrid composition as compared to the polypropylene mesh. In particular,the polypropylene mesh showed inflammation, greater contraction, hadhematomas present, intestinal adhesion, and included a presence of fattissue in each of the three explants. The polypropylene mesh also hadonly a thin layer of connective tissue surrounding the mesh. Incontrast, the hybrid composition mesh included less inflammation, lesscontraction, no intestinal adhesions and good/healthy tissue ingrowth ineach of the three explants.

Vimentin staining showed similar results of fibroblasts ormyofibroblasts in both the polypropylene mesh and the hybridcomposition. The SMA staining was stronger in the polypropylene meshthan the hybrid composition, indicating that more myofibroblasts werepresent in the polypropylene mesh than the hybrid composition. The SMAstaining also correlated to the contraction observations in thepolypropylene mesh. An abundance of endothelial cells was present inboth the polypropylene mesh and the hybrid composition. It is furthernoted that the hybrid composition was dimensioned two or more timesgreater in thickness than the polypropylene mesh. Based on theseresults, the hybrid composition provides the requisite support to thedefect area while reducing or preventing inflammation, and furtherpromoting healthy tissue ingrowth.

Six Week Study

Explants of the polypropylene mesh and the hybrid composition wereobtained after six weeks. No intestinal adhesion was observed for thecomposition. In addition, the biologic material maintained a strongattachment to the synthetic material due to the physical rubbing and/orcompression of the biologic material into the synthetic material duringfabrication.

The H&E stained views of the polypropylene mesh and the hybridcomposition indicated that the hybrid composition thickness was two ormore times greater than the thickness of the polypropylene mesh. Inaddition, the polypropylene mesh showed a greater amount of inflammationthan the hybrid composition. Any inflammation present in the hybridcomposition was concentrated around the synthetic mesh fibers. It isnoted that the hybrid composition had less inflammation than the threeweek histology discussed above.

The H&E stained views of the polypropylene mesh and hybrid compositionfurther showed that the polypropylene mesh had good integration with thehost tissue at the implant-host interface. Although the hybridcomposition had a poor implant-host interface, this was attributed to animproper surgery technique. If the surgical technique is properlyperformed, the implant-host interface of the hybrid composition isexpected to have strong and healthy tissue ingrowth, as well as lowinflammation levels.

The H&E stained views of the polypropylene mesh and hybrid compositionshowed that the polypropylene mesh container a large amount ofinflammation while the hybrid composition contained minimal inflammationwith the inflammation mainly centered around the synthetic fibers.Multiple blood vessels formed in the polypropylene mesh due toinflammation, while multiple blood vessels formed in the hybridcomposition due to tissue ingrowth. Overall, the hybrid composition atsix weeks had less inflammation and a denser tissue matrix than eitherthe polypropylene mesh at six weeks or the hybrid composition at threeweeks.

Smooth muscle actin (SMA) stained tissue sections of the polypropylenemesh and the hybrid composition were obtained six weeks afterimplantation in the rat abdominal wall model. The stronger staining inthe polypropylene mesh indicated that there are more myofibroblastspresent in the polypropylene mesh than in the hybrid composition. Thestaining further showed an abundance of blood vessel formation in thehybrid composition, indicating strong tissue ingrowth and integrationwith the host tissue.

Six Week Study Results

The six week histology study indicated advantageous properties of thehybrid composition as compared to the polypropylene mesh. In particular,the polypropylene mesh showed a persistence in inflammation from thethree week explant, the presence of hematomas, fat tissue lining theinner portion of the polypropylene mesh, and a thin layer of connectivetissue surrounding the polypropylene mesh in each of the three explants.In contrast, the hybrid composition included a reduction in inflammationas compared to the three week explant (except for slight inflammationaround the synthetic fibers), showed a strong cellular response andtissue ingrowth (e.g., abundant vessels present, a dense matrix ascompared to the three week explant, and the like), and remaineddimensioned more than two times thicker than the polypropylene mesh.

Based on these results, the hybrid composition retained the tensilestrength of the synthetic material or mesh throughout processing. Thehybrid composition also induced a better biologic response than theuncoated polypropylene mesh. The hybrid composition therefore promotedtissue ingrowth, reduced organ adhesion, reduced contraction, andreduced inflammation. Thus, the hybrid composition provides an improvedbiologic response post-implantation and retains a strong attachmentbetween the synthetic and biologic materials over time.

FIGS. 20 and 21 show gross images of a synthetic mesh explant and FIGS.22 and 23 show a non-compressed hybrid sponge or composition explant.The synthetic mesh and the non-compressed hybrid composition were usedto repair a defect in the rat abdominal wall. FIG. 20 shows a defectrepaired with the synthetic mesh and FIG. 22 shows a defect repairedwith the non-compressed composition, while FIG. 21 shows across-sectional image of the explanted synthetic mesh and FIG. 23 showsa cross-sectional image of the explanted non-compressed composition. Theexplanted synthetic mesh defines a thinner width than the non-compressedcomposition. In addition, intestinal adhesions (shown by the arrow inFIG. 20) to the synthetic mesh were observed in 33% of defects repairedwith the synthetic mesh. No adhesions were observed in defects repairedwith the non-compressed compositions.

FIG. 24 is a hematoxylin and eosin (H&E) image of an explant of a ratabdominal wall defect repaired with a synthetic mesh, and FIG. 25 is anH&E image of an explant of a rat abdominal wall defect repaired with anon-compressed composition. The synthetic mesh explants showed amultitude of inflammatory cells surrounding the synthetic material aswell as throughout the rest of the repaired area. The non-compressedcomposition explants showed minimal inflammation around the syntheticmaterial with even and abundant infiltration of fibroblast-like cellsthroughout the rest of the repaired areas. FIG. 26 is an H&E imageshowing blood vessels visible in a non-compressed composition explant.In particular, the arrows in FIG. 26 show the abundant blood vesselsformed and visible in the non-compressed composition explant.

FIG. 27 shows a smooth muscle actin (SMA) stain of an explant of a ratabdominal wall defect repaired with a synthetic mesh, and FIG. 28 is anSMA stain of an explant of a rat abdominal wall defect repaired with anon-compressed composition. SMA is present in both myofibroblasts andendothelial cells. The synthetic mesh explant of FIG. 27 shows anabundance of SMA containing cells, many of which also align (in adiagonal direction), indicating a strong presence of myofibroblasts.Some blood vessels are also present as shown by the circular brownstaining. The hybrid non-compressed composition of FIG. 28 shows sparseand localized areas of SMA containing cells, indicating a lack ofmyofibroblasts and presence of blood vessels.

FIG. 29 is a chart of a size of an original rat abdominal wall defectand a repaired rat abdominal wall defect for defects repaired with asynthetic mesh and a non-compressed composition. The bar on the left foreach material indicates the head to tail direction measurement, whilethe bar on the right for each material indicates the side to sidedirection measurement of the abdominal wall defect. The data of FIG. 29indicates that the pre-implant material or original abdominal walldefect has the greatest measurements, the hybrid non-compressedcomposition has the next lowest measurements, and the synthetic mesh hasthe lowest measurements for the repaired abdominal wall defect. Defectsrepaired with synthetic mesh alone contracted more and became smallerthan those repaired with hybrid non-compressed compositions. This datawas found to be consistent with the SMA staining data which showed moremyofibroblasts (cells responsible for contraction) in the synthetic meshexplant than the hybrid non-compressed composition explant.

FIG. 18 is a cross-sectional view of an exemplary compressed hybridsponge or composition 180. The composition 180 includes a syntheticmaterial 184 disposed between and compressed by the biologic material182. FIG. 19 is an SEM image of the compressed composition 180 showingthe synthetic material 184 encased by the biologic material 182.

FIG. 30 is an H&E image showing compressed compositions implanted in arat subcutaneous space for four weeks. The compressed hybrid sponge orcomposition showed minimal inflammation around the synthetic materialwith even and abundant infiltration of fibroblast-like cells and vesselsthroughout the rest of the repaired areas, similar to the biologicresponse to the non-compressed compositions. This data suggests thatcompression does not adversely affect the biologic response.

The bio-synthetic hybrid composition provides a surgicalthree-dimensional scaffold for tissue repair, attachment, reinforcement,reconstruction, or combinations thereof, which advantageously minimizescomplications and promotes tissue ingrowth, leading to an overallimproved surgical outcome. The inherent biomechanical strength due tothe synthetic material or component (absorbable or non-absorbable) canbe on several orders of magnitude higher than the biologic materialalone. The biologic material or component can be manufactured to anyshape, size, porosity, or stiffness, while maintaining the biologicaladvantages associates with biologic materials (e.g., rapidrevascularization, cell repopulation, white cell migration, orcombinations thereof). Therefore, the exemplary compositions can be usedin a wide array of applications, such as trocar, laparoscopic, hemostat,hernia, abdominal wall, soft tissue repair, fistula, pelvic organprolapse, or hysterectomy.

Although the compositions and methods of the present disclosure havebeen described with reference to exemplary embodiments thereof, thepresent disclosure is not limited to such exemplary embodiments and orimplementations. Rather, the compositions and methods of the presentdisclosure are susceptible to many implementations and applications, aswill be readily apparent to persons skilled in the art from thedisclosure hereof. The present disclosure expressly encompasses suchmodifications, enhancements and or variations of the disclosedembodiments. Since many changes could be made in the above exemplaryembodiments and many widely different embodiments of this disclosurecould be made without departing from the scope thereof, it is intendedthat all matter contained in the drawings and specification shall beinterpreted as illustrative and not in a limiting sense. Additionalmodifications, changes, and substitutions are intended in the foregoingdisclosure. Accordingly, it is appropriate that the appended claims beconstrued broadly and in a manner consistent with the scope of thedisclosure.

What is claimed is:
 1. A composition for treatment, comprising: asynthetic material; and a collagen-containing tissue matrix encasing thesynthetic material; wherein the collagen-containing tissue matrix is inthe form of a freeze dried slurry that prior to freeze drying includedbetween 5% and 35% by volume of the collagen-containing tissue matrixsubjected to an acid-swelling process; and wherein at least a portion ofthe collagen-containing tissue matrix comprises a smooth layer or skinon a surface of the composition produced during freeze drying of theslurry.
 2. The composition of claim 1, wherein the slurry ismechanically moved or rubbed into the synthetic material to force atleast some of the slurry into openings in an outer surface of thesynthetic material.
 3. The composition of claim 1, wherein the smoothlayer or skin is on an upper surface and an opposing lower surface ofthe composition is produced during freeze drying of the slurry.
 4. Thecomposition of claim 1, wherein the composition comprises anantimicrobial compound.
 5. The composition of claim 1, wherein thecomposition comprises an anti-inflammatory compound.
 6. The compositionof claim 1, wherein at least some of the slurry is disposed withinopenings in an outer surface of the synthetic material.
 7. Thecomposition of claim 1, wherein the tensile strength of the syntheticmaterial is greater than a tensile strength of the collagen-containingtissue matrix.
 8. The composition of claim 1, wherein the syntheticmaterial is biocompatible.
 9. The composition of claim 1, wherein thesynthetic material comprises at least one of polypropylene,polytetrafluoroethylene, polyester, terephthalate, polyglycolide, orpoly-4-hydroxybutyrate.
 10. The composition of claim 1, wherein thesynthetic material comprises textured surfaces.
 11. The composition ofclaim 1, wherein the collagen-containing tissue matrix is in the form ofthe freeze dried slurry that prior to freeze drying included between 5%and 25% by volume of the collagen-containing tissue matrix subjected tothe acid-swelling process.
 12. The composition of claim 1, wherein thecollagen-containing tissue matrix is in the form of the freeze driedslurry that prior to freeze drying included between 5% and 10% by volumeof the collagen-containing tissue matrix subjected to the acid-swellingprocess.
 13. The composition of claim 1, wherein the acid-swellingprocess comprises suspending the collagen-containing tissue matrix inacid and incubating the collagen-containing tissue matrix in the aciduntil swelling occurs.
 14. The composition of claim 1, wherein prior tofreeze drying, the collagen-containing tissue matrix was decellularized.15. The composition of claim 1, wherein prior to freeze drying, theslurry was resuspended in a buffer.
 16. The composition of claim 1,wherein the synthetic material comprises at least one of a porous foam,a planar mesh, a monofilament woven material, a multifilament wovenmaterial, multi-leveled layers, or multi-directional layers.
 17. Thecomposition of claim 1, wherein a tensile strength of the syntheticmaterial is greater than a tensile strength of the collagen-containingtissue matrix.
 18. The composition of claim 1, wherein thecollagen-containing tissue matrix comprises an acellular tissue matrix.19. The composition of claim 1, wherein prior to freeze drying, thecollagen-containing tissue matrix comprises a group ofcollagen-containing tissue matrix fragments, at least a portion of thecollagen-containing tissue matrix fragments including frayed ends.
 20. Amethod of treatment, comprising: selecting an anatomic site; andimplanting in or on the anatomic site a composition according to claim1.